Polyolefin resins are generally relatively inexpensive and have excellent properties, such as resistance to drugs, water, and heat, and are used in a wide array of fields as material for automobile parts, electronic components, building material, wrapping film, and the like. Polyolefin resins are, however, crystalline and non-polar and thus difficult to apply and adhere. For this reason, chlorinated polyolefins, which bind polyolefin resin tightly, have been used as a binder resin in order to apply and adhere such hard-to-adhere polyolefin resins.
For the most part, however, these binder compositions are used in a dissolved form in organic solvents such as toluene or xylene, and thus a large amount of the organic solvent is released into the air during application, which has raised concerns with regard to environment pollution.
Accordingly, aqueous resin compositions that contain chlorinated polyolefin and surfactant conventionally have been proposed as polyolefin resin compositions that can be dissolved without the use of organic solvent (see Patent Documents 1 and 2)
Patent Document 1 discloses a method of heating a mixture of polyvalent alcohol and a surfactant together, adding a chlorinated polyolefin resin and heating further, and then adding a primary, secondary, or tertiary amine and mixing and melting these while adding water gradually to the melted mass that is formed in order to obtain a desired aqueous resin composition.
Patent Document 2 discloses a method of mixing, heating, and stirring of a chlorinated polyolefin resin, a surfactant, a primary, secondary, or tertiary amine, and water in order to obtain a desired aqueous resin composition.
However, both of these conventional aqueous resin compositions use a resin with a low molecular weight, and thus have the problem that the aqueous resin compositions do not realize their expected properties.
Further, in the case of the aqueous resin compositions shown in Patent Document 1, water is added to the melted mass gradually in order to obtain the desired composition, and this requires a complicated dilution procedure.
Patent Document 1: JP H4-506530A
Patent Document 2: JP H6-509130A